package main
import (
	"fmt"
	"math/rand"
	"math"
)

func main(){
   var sum float64 = 0
   fmt.Println("我现在的值为",sum)

   for math.Abs(sum-20)>0.01 {
	 var r = rand.Intn(3)+1
	if r == 1{
      sum+=0.05
	}else if r == 2{
		 sum+=0.2
	}else{
         sum+=0.25 
	}
	 
	fmt.Printf("%.6f\n",sum)
   }
}